Thiosulfenyl dithiocarbamates as grain insect repellents



Patented Dec. 9, 1952 UNITED STATES ?ATENT OFFICE THIOSULFENYL DITHIOCARBAMATES AS GRAIN INSECT REPELLENTS No Drawing. Application May 5, 1950, Serial No. 160,384

15 Claims. 1

saw-toothed beetle, Oryaaephilus surinamensis Linn; cadelle beetle, Teneb'roides mauritam'cus Linn; granary Weevil, Sitophilus granarius Linn; cigarette beetle or towbug, Lasioderma sern'corne Fabricus; and mealworms, Tenebrio molitor Linn and Teniebrz'o obscurus Fabricus. These compounds may be represented by the general formula wherein each R is selected from the group consisting of hydrogen, alkyl, aryl and aralkyl radicals, having not more than carbon atoms, and not more than one R being hydrogen and wherein R is selected from the group consisting of primary, secondary and tertiary alkyl radicals containing not more than 10 carbon atoms; n is an integer from the group of 2 and 3. A method for the production of these compounds when n is 2, from the interaction of sulfenyl halides with salts of N-substituted dithiocarbamic acids is disclosed in copending application, Serial Number 772,218, filed by Himel et al., on September 4, 1947. A method for the production of these compounds when n is 3, from the interaction of thiosulfenyl halides with salts of N-substituted dithiocarbamic acids is disclosed in c-opending application, Serial Number 59,025, filed by Himel et al., on November 8, 1M8.

Typical compounds applicable to the present invention when n is 2 include N-isopropyl-S-tertbutylsulfenyl dithiocarbamate, N,N-diethyl-S- tert-butylsulfenyl dithiocarbamate, N,N-dinpropyl S tert butylsulfenyl dithiocarbamate, N,N dimethyl S -tert butylsulfenyl dithiocarbamate, piperidine-S-tert-butylsulfenyl dithiocarbamate, N,N-di-n-dodecyl-S-tert-butylsulfenyl dithiocarbamate, N,N-diethyl-S-n-hexylsulfenyl dithiocarbamate and the like. Typical compounds applicable to the present invention when n is 3 include N,N-diethyl-S-tert-butylthiosulfenyl dithiocarbamate, N,N-dimethyl-S- tert-butylthiosulfenyl dithiocarbamate, piperidine-S-tert-butylthiosulfenyl dithiocarbamate, N,N-di-n-propyl-S-tert-butylthiosulfenyl dithiocarbamate, N,N-di-n-propyl-S-n-butylthiosulfenyl dithiocarbamate and the like.

Although sulfenyl dithiocarbamates have been reported to be useful as insecticides, no test results were concomitantly recorded to substantiate said report. We have found by laboratory tests that sulfenyl dithiocarbamates display limited insecticidal activity against flies and a very limited toxicity against roaches. However, they by no means have comparable toxicity to DDT type compounds and other commercially important insecticidal materials.

Using the microtopical application technique We have found that N,N-dimethyl-S-tert-butylsulfenyl dithiocarbamate was relatively inefiective at a concentration of one per cent in a nontoxic solvent against houseflies M usca domestica. Since DDT is generally per cent effective at a concentration of only 0.2 per cent it is seen that sulfenyl dithiocarbamates have relatively limited toxicity. These observations are reported in the following table.

N,N-dimethyl-S-tert-butylsulfenyl dithiocarbamate was also tested against American roaches Periplaneta. americana by the racetrack method. This method employs a stainless steel hoop 3 inches high and 30 inches in diameter in which large nymphs are sprayed with the chemical to be tested. The inner wall of the hoop is greased to prevent escape of the roaches. The spray was applied with a nasal atomizer in a Feet-Grady chamber. The compound was applied at 2 grams in 25 cc. of Soltrol (a non-toxic solvent). The compound irritated the roaches considerably but none was dead at the end of 24 hours. Even after two weeks mortality was only 60 per cent.

1 The microtopical method comprises treating individual insects with a small amount of a solution of the candi date insecticide in a non-toxic solvent. When using flies as the test insect the solution is applied to the pronotum. When roaches are used as the test insect the solution is applied to the first ventral abdominal segment. Application'is made by means of suitable microtopical application apparatus such as a hypodermic needle and syringe.

The confused flour beetle is an important pest of stored grain and grain products such as wheat flour and the like. The task of controlling this insect is made difiicult by the fact that the product it harms must not be contaminated with poisonous or otherwise objectionable chemicals. To date no very satisfactory control of these beetles is known.

The fact that sulfenyl and thiosulfenyl dithiocarbamates are highly effective repellents against confused flour beetles Tribelium confusum is surprising and unexpected. When paper or cloth bags, used as containers for grain or grain prodnets, are impregnated with a compound of the present invention, an effective barrier is provided which prevents entrance of beetles to the product contained therein.

The compounds of the present invention may be applied for their intended purpose in any suitable manner. For example they may be applied in the form of solutions, dusts, emulsions, aerosols, fogs and the like to areas where it is desired to repel flour beetles.

Any suitable carrier or solvent may be employed which is inert with respect to the active insect repellent. Examples of suitable solvents or carriers include straight and branched chain hydrocarbons such as n-pentane and isoheptane, cyclic paraffinic hydrocarbons containing at least five carbon atoms such as cyclooctane and mixtures of such hydrocarbons. Talc, kieselguhr and other inert carriers may be used in preparing dusts. Water may be used advantageously to form emulsions of said compounds for spraying. When preparing aqueous emulsions, wetting or emulsifying agents such as Triton X 100 (alkyl aryl polyether alcohol), Dresinate 731 (sodium salt of a disproportionated rosin acid), Tween (sorbitan monolaurate polyethylene oxide) and the like are employed in suflicient quantity to stabilize the emulsion.

The flour beetle repellents of the present invention may be applied in any suitable concentration or the compound may be applied per se. We have found that solutions or emulsions containing from 1 to 20 per cent by weight of the active ingredient may be applied as a spray to cover areas which are to be kept free of insect pasts.

EXAMPLE I Flour beetles dislike light and avoid it whenever possible. This fact is the basis for the presently employed method of testing beetle repellents.

One hundred beetles were placed in a 6 inch Petri dish. This container was chosen because it was a convenient size and shape and, as it was glass, the beetles were unable to crawl up the sides to escape. Two cardboard shelters were placed in the dish over a small amount of wheat fiour. Each shelter was one-half of a cardboard disk cut on the diameter. These disks were the tops of lids of one pint ice cream cartons. One of these shelters was untreated and the other was treated with cc. of a l per cent solution or 5 mg. of the candidate repellent. The amount of solution was chosen as necessary to give adequate coverage in treating the shelter.

The Petri dishes were placed in the light and the beetles sought darkness under the shelters. If the treated shelter was repellent to them they were all found under the untreated shelter. R sults of tests on several sulfenyl and thiosulfenyl dithiocarbamates are reported in the following table. Readings were made on the first and sec- 0nd days after the test was set up, and on alternate days thereafter.

Pyrethrum was used as a standard. It is the one material which is used commercially at the present time as a flour beetle repellent.

Compound Name N,N diethyl S tert butylthiosulfenyl dithiocarbamate.

N-isopropyl-tcrtbutylsulfenyl dithiocarbamate.

N,N-diethyl-tert-butylsulienyl dithiocarbamate.

. N,N dimethyl tert butylthiosulfenyl dithiocarbamate. N,N-dimethyl-tcrt-butylsulfcnyl dithiocarbamate. Piperidine-tert-hutylthiosull'enyl dithiocarbamate.

Percent of beetles in treated shelter Compound 1 2 4 6 8 l0 12 14 day days days days days days days days A 3 2 2 10 l5 l2 l5 15 B 5 2 5 5 10 l2 l2 15 C 3 3 6 8 12 15 12 15 D 0 1 0 2 G) E 0 0 0 0 l 2 5 2 5 1 5 F l0 6 10 l2 15 25 25 25 Pyrethrum 2 4 2 3 l4 6 8 2O 1 inadvertently discontinued. 1 Beetles dead.

EXAMPLE II A standard grocery store paper bag was impregnated with each compound listed below and then filled with flour following which it was placed in large open containers filled with fly media infected with the confused flour beetle, Tribolium confusum and stored at about 82 F. for three months. The bags measured four by six inches and were treated with mg. of the compound in acetone which was then evaporated.

A few drops of an acetone solution of pure N,N- dimethyl-tert-butylsulfenyl dithiocarbamate was applied to a Ralston-Purina dog chow checker which, after evaporation of the acetone, was then placed in a cage with ten roaches that had been starved for a week. Water was provided. Readings were made at intervals. The roaches began to nibble on the checker immediately but were repelled and presumably never touched it again. When the test was discontinued four weeks later the checker still had not been eaten although the roaches had had no other food in five weeks. Two of the roaches were dead but it is not known whether this was from eating on the treated checker, exposure to the chemical, or merely to starvation. In any event the repellent character of this material was striking.

Reasonable variation and modification are possible within the scope of the foregoing disclosure and the appended claims to the invention, the essence of which is that the compounds set forth have been surprisingly and unexpectedly discovered to be insect repellents.

We claim:

1. A method for repelling insects which frequent grain and grain products which comprises applying to the place or material from which the insect is to be repelled a repelling amount of a compound represented by the general formula wherein each R is selected from the group consisting of hydrogen, alkyl, aryl and aralkyl radicals, having not more than carbon atoms, and wherein the two Rs together form a, pentamethylene radical and not more than one R being hydrogen and wherein R is selected from the group consisting of primary, secondary and tertiary alkyl radicals containing not more than 10 carbon atoms, n is 3, and a fluid carrier,

2. The method according to claim 1 wherein the said compound is N,N-dimethyl-tert-butylthiosulfenyl dithiocarbamate.

3. A method of repelling insects which frequent grain and grain products which comprises applying to the place or material from which said insects are to be repelled a repelling amount of N,N-dimethyl-tert-butylthiosulfenyl dithiocarbamate dissolved in a hydrocarbon solvent containing at least 5 carbon atoms.

4. A method for repelling insects which frequent grain and grain products which comprises applying a repelling amount of a thiosulfenyl dithiocarbamate to the locus from which said insects are to be repelled.

5. A method for repelling insects which frequent grain and grain products which comprises applying to the locus from which said insects are to be repelled a repelling amount of N,N- dimethyl S tert butylthiosulfenyl dithiocarbamate.

6. A method for repelling insects which frequent grain and grain products which comprises applying to the locus from which said insects are to be repelled a repelling amount of N,N-diethyl- S-tert-butylthiosulfenyl dithiocarbamate.

7. A method for repelling insects which frequent grain and grain products which comprises applying to the locus from which said insects are to be repelled a repelling amount of piperidine- S-tert-butylthiosulfenyl dithiocarbamate.

8. A method for repelling insects which frequent grain and grain products which comprises applying to th locus from which said insects are to be repelled a repelling amount of N,N-din propyl S tert butylthiosulfenyl dithiocarbamate.

9. A method for repelling insects which frequent grain and grain products which comprises applying to the locus from which said insects are to be repelled a repelling amount of N,N-di-npropyl-S-n-butylthiosulfenyl dithiocarbamate.

10. An absorbent container constructed from a material selected from the group consisting of paper and cloth impregnated with an amount effective to repel insects which frequent grain and grain products of a compound represented by the general formula wherein each R is selected from the group consisting of hydrogen, alkyl, aryl, and aralkyl radicals, having not more than 10 carbon atoms, and wherein the two Rs together form a pentamethylene radical, and not more than one B being hydrogen and wherein R is selected from the group consisting of primary, secondary and tertiary alkyl radicals containing not more than 10 carbon atoms, and n is 3.

11. The container of claim 10 wherein the compound is a thiosulfenyl dithiocarbamate.

12. The container of claim 10 wherein the compound is N,N-dimethyl-S-tert-butylthiosulfenyl dithiocarbamate.

13. The container of claim 10 wherein the compound is N,N-diethyl-S-tert-butylthiosulfenyl dithiocarbamate.

14. The container of claim 10 wherein the compound is N,N-di-n-propyl-S-tert-butylthiosulfenyl dithiocarbamate.

15. The container of claim 10 wherein the compound is piperidine-tert-butylthiosulfenyl dithiocarbamate.

- LYLE D. GOODHUE.

CAROLYN E. TISSOL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,344,105 Peters Mar. 14, 1944 2,359,266 Hechenbleilmer Sept. 26, 1944 2,390,713 Hunt Dec. 11, 1945 2,469,340 Payne May 3, 1949 

4. A METHOD FOR REPELLING INSECTS WHICH FREQUENT GRAIN AND GRAIN PRODUCTS WHICH COMPRISES APPLYING A REPELLING AMOUNT OF A THIOSULFENYL DITHIOCARBAMATE TO THE LOCUS FROM WHICH SAID INSECTS ARE TO BE REPELLED. 